1
2
3
4
5#include <linux/sched.h>
6#include <linux/posix-timers.h>
7#include <linux/errno.h>
8#include <linux/math64.h>
9#include <asm/uaccess.h>
10#include <linux/kernel_stat.h>
11#include <trace/events/timer.h>
12
13
14
15
16
17
18
19void update_rlimit_cpu(struct task_struct *task, unsigned long rlim_new)
20{
21 cputime_t cputime = secs_to_cputime(rlim_new);
22
23 spin_lock_irq(&task->sighand->siglock);
24 set_process_cpu_timer(task, CPUCLOCK_PROF, &cputime, NULL);
25 spin_unlock_irq(&task->sighand->siglock);
26}
27
28static int check_clock(const clockid_t which_clock)
29{
30 int error = 0;
31 struct task_struct *p;
32 const pid_t pid = CPUCLOCK_PID(which_clock);
33
34 if (CPUCLOCK_WHICH(which_clock) >= CPUCLOCK_MAX)
35 return -EINVAL;
36
37 if (pid == 0)
38 return 0;
39
40 rcu_read_lock();
41 p = find_task_by_vpid(pid);
42 if (!p || !(CPUCLOCK_PERTHREAD(which_clock) ?
43 same_thread_group(p, current) : has_group_leader_pid(p))) {
44 error = -EINVAL;
45 }
46 rcu_read_unlock();
47
48 return error;
49}
50
51static inline union cpu_time_count
52timespec_to_sample(const clockid_t which_clock, const struct timespec *tp)
53{
54 union cpu_time_count ret;
55 ret.sched = 0;
56 if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) {
57 ret.sched = (unsigned long long)tp->tv_sec * NSEC_PER_SEC + tp->tv_nsec;
58 } else {
59 ret.cpu = timespec_to_cputime(tp);
60 }
61 return ret;
62}
63
64static void sample_to_timespec(const clockid_t which_clock,
65 union cpu_time_count cpu,
66 struct timespec *tp)
67{
68 if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED)
69 *tp = ns_to_timespec(cpu.sched);
70 else
71 cputime_to_timespec(cpu.cpu, tp);
72}
73
74static inline int cpu_time_before(const clockid_t which_clock,
75 union cpu_time_count now,
76 union cpu_time_count then)
77{
78 if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) {
79 return now.sched < then.sched;
80 } else {
81 return cputime_lt(now.cpu, then.cpu);
82 }
83}
84static inline void cpu_time_add(const clockid_t which_clock,
85 union cpu_time_count *acc,
86 union cpu_time_count val)
87{
88 if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) {
89 acc->sched += val.sched;
90 } else {
91 acc->cpu = cputime_add(acc->cpu, val.cpu);
92 }
93}
94static inline union cpu_time_count cpu_time_sub(const clockid_t which_clock,
95 union cpu_time_count a,
96 union cpu_time_count b)
97{
98 if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) {
99 a.sched -= b.sched;
100 } else {
101 a.cpu = cputime_sub(a.cpu, b.cpu);
102 }
103 return a;
104}
105
106
107
108
109
110
111
112static inline cputime_t cputime_div_non_zero(cputime_t time, unsigned long div)
113{
114 cputime_t res = cputime_div(time, div);
115
116 return max_t(cputime_t, res, 1);
117}
118
119
120
121
122
123static void bump_cpu_timer(struct k_itimer *timer,
124 union cpu_time_count now)
125{
126 int i;
127
128 if (timer->it.cpu.incr.sched == 0)
129 return;
130
131 if (CPUCLOCK_WHICH(timer->it_clock) == CPUCLOCK_SCHED) {
132 unsigned long long delta, incr;
133
134 if (now.sched < timer->it.cpu.expires.sched)
135 return;
136 incr = timer->it.cpu.incr.sched;
137 delta = now.sched + incr - timer->it.cpu.expires.sched;
138
139 for (i = 0; incr < delta - incr; i++)
140 incr = incr << 1;
141 for (; i >= 0; incr >>= 1, i--) {
142 if (delta < incr)
143 continue;
144 timer->it.cpu.expires.sched += incr;
145 timer->it_overrun += 1 << i;
146 delta -= incr;
147 }
148 } else {
149 cputime_t delta, incr;
150
151 if (cputime_lt(now.cpu, timer->it.cpu.expires.cpu))
152 return;
153 incr = timer->it.cpu.incr.cpu;
154 delta = cputime_sub(cputime_add(now.cpu, incr),
155 timer->it.cpu.expires.cpu);
156
157 for (i = 0; cputime_lt(incr, cputime_sub(delta, incr)); i++)
158 incr = cputime_add(incr, incr);
159 for (; i >= 0; incr = cputime_halve(incr), i--) {
160 if (cputime_lt(delta, incr))
161 continue;
162 timer->it.cpu.expires.cpu =
163 cputime_add(timer->it.cpu.expires.cpu, incr);
164 timer->it_overrun += 1 << i;
165 delta = cputime_sub(delta, incr);
166 }
167 }
168}
169
170static inline cputime_t prof_ticks(struct task_struct *p)
171{
172 return cputime_add(p->utime, p->stime);
173}
174static inline cputime_t virt_ticks(struct task_struct *p)
175{
176 return p->utime;
177}
178
179static int
180posix_cpu_clock_getres(const clockid_t which_clock, struct timespec *tp)
181{
182 int error = check_clock(which_clock);
183 if (!error) {
184 tp->tv_sec = 0;
185 tp->tv_nsec = ((NSEC_PER_SEC + HZ - 1) / HZ);
186 if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) {
187
188
189
190
191
192 tp->tv_nsec = 1;
193 }
194 }
195 return error;
196}
197
198static int
199posix_cpu_clock_set(const clockid_t which_clock, const struct timespec *tp)
200{
201
202
203
204
205 int error = check_clock(which_clock);
206 if (error == 0) {
207 error = -EPERM;
208 }
209 return error;
210}
211
212
213
214
215
216static int cpu_clock_sample(const clockid_t which_clock, struct task_struct *p,
217 union cpu_time_count *cpu)
218{
219 switch (CPUCLOCK_WHICH(which_clock)) {
220 default:
221 return -EINVAL;
222 case CPUCLOCK_PROF:
223 cpu->cpu = prof_ticks(p);
224 break;
225 case CPUCLOCK_VIRT:
226 cpu->cpu = virt_ticks(p);
227 break;
228 case CPUCLOCK_SCHED:
229 cpu->sched = task_sched_runtime(p);
230 break;
231 }
232 return 0;
233}
234
235void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times)
236{
237 struct signal_struct *sig = tsk->signal;
238 struct task_struct *t;
239
240 times->utime = sig->utime;
241 times->stime = sig->stime;
242 times->sum_exec_runtime = sig->sum_sched_runtime;
243
244 rcu_read_lock();
245
246 if (!likely(pid_alive(tsk)))
247 goto out;
248
249 t = tsk;
250 do {
251 times->utime = cputime_add(times->utime, t->utime);
252 times->stime = cputime_add(times->stime, t->stime);
253 times->sum_exec_runtime += t->se.sum_exec_runtime;
254 } while_each_thread(tsk, t);
255out:
256 rcu_read_unlock();
257}
258
259static void update_gt_cputime(struct task_cputime *a, struct task_cputime *b)
260{
261 if (cputime_gt(b->utime, a->utime))
262 a->utime = b->utime;
263
264 if (cputime_gt(b->stime, a->stime))
265 a->stime = b->stime;
266
267 if (b->sum_exec_runtime > a->sum_exec_runtime)
268 a->sum_exec_runtime = b->sum_exec_runtime;
269}
270
271void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times)
272{
273 struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
274 struct task_cputime sum;
275 unsigned long flags;
276
277 spin_lock_irqsave(&cputimer->lock, flags);
278 if (!cputimer->running) {
279 cputimer->running = 1;
280
281
282
283
284
285
286 thread_group_cputime(tsk, &sum);
287 update_gt_cputime(&cputimer->cputime, &sum);
288 }
289 *times = cputimer->cputime;
290 spin_unlock_irqrestore(&cputimer->lock, flags);
291}
292
293
294
295
296
297static int cpu_clock_sample_group(const clockid_t which_clock,
298 struct task_struct *p,
299 union cpu_time_count *cpu)
300{
301 struct task_cputime cputime;
302
303 switch (CPUCLOCK_WHICH(which_clock)) {
304 default:
305 return -EINVAL;
306 case CPUCLOCK_PROF:
307 thread_group_cputime(p, &cputime);
308 cpu->cpu = cputime_add(cputime.utime, cputime.stime);
309 break;
310 case CPUCLOCK_VIRT:
311 thread_group_cputime(p, &cputime);
312 cpu->cpu = cputime.utime;
313 break;
314 case CPUCLOCK_SCHED:
315 cpu->sched = thread_group_sched_runtime(p);
316 break;
317 }
318 return 0;
319}
320
321
322static int posix_cpu_clock_get(const clockid_t which_clock, struct timespec *tp)
323{
324 const pid_t pid = CPUCLOCK_PID(which_clock);
325 int error = -EINVAL;
326 union cpu_time_count rtn;
327
328 if (pid == 0) {
329
330
331
332
333 if (CPUCLOCK_PERTHREAD(which_clock)) {
334
335
336
337 error = cpu_clock_sample(which_clock,
338 current, &rtn);
339 } else {
340 read_lock(&tasklist_lock);
341 error = cpu_clock_sample_group(which_clock,
342 current, &rtn);
343 read_unlock(&tasklist_lock);
344 }
345 } else {
346
347
348
349
350 struct task_struct *p;
351 rcu_read_lock();
352 p = find_task_by_vpid(pid);
353 if (p) {
354 if (CPUCLOCK_PERTHREAD(which_clock)) {
355 if (same_thread_group(p, current)) {
356 error = cpu_clock_sample(which_clock,
357 p, &rtn);
358 }
359 } else {
360 read_lock(&tasklist_lock);
361 if (thread_group_leader(p) && p->sighand) {
362 error =
363 cpu_clock_sample_group(which_clock,
364 p, &rtn);
365 }
366 read_unlock(&tasklist_lock);
367 }
368 }
369 rcu_read_unlock();
370 }
371
372 if (error)
373 return error;
374 sample_to_timespec(which_clock, rtn, tp);
375 return 0;
376}
377
378
379
380
381
382
383
384static int posix_cpu_timer_create(struct k_itimer *new_timer)
385{
386 int ret = 0;
387 const pid_t pid = CPUCLOCK_PID(new_timer->it_clock);
388 struct task_struct *p;
389
390 if (CPUCLOCK_WHICH(new_timer->it_clock) >= CPUCLOCK_MAX)
391 return -EINVAL;
392
393 INIT_LIST_HEAD(&new_timer->it.cpu.entry);
394
395 rcu_read_lock();
396 if (CPUCLOCK_PERTHREAD(new_timer->it_clock)) {
397 if (pid == 0) {
398 p = current;
399 } else {
400 p = find_task_by_vpid(pid);
401 if (p && !same_thread_group(p, current))
402 p = NULL;
403 }
404 } else {
405 if (pid == 0) {
406 p = current->group_leader;
407 } else {
408 p = find_task_by_vpid(pid);
409 if (p && !has_group_leader_pid(p))
410 p = NULL;
411 }
412 }
413 new_timer->it.cpu.task = p;
414 if (p) {
415 get_task_struct(p);
416 } else {
417 ret = -EINVAL;
418 }
419 rcu_read_unlock();
420
421 return ret;
422}
423
424
425
426
427
428
429
430static int posix_cpu_timer_del(struct k_itimer *timer)
431{
432 struct task_struct *p = timer->it.cpu.task;
433 int ret = 0;
434
435 if (likely(p != NULL)) {
436 read_lock(&tasklist_lock);
437 if (unlikely(p->sighand == NULL)) {
438
439
440
441
442 BUG_ON(!list_empty(&timer->it.cpu.entry));
443 } else {
444 spin_lock(&p->sighand->siglock);
445 if (timer->it.cpu.firing)
446 ret = TIMER_RETRY;
447 else
448 list_del(&timer->it.cpu.entry);
449 spin_unlock(&p->sighand->siglock);
450 }
451 read_unlock(&tasklist_lock);
452
453 if (!ret)
454 put_task_struct(p);
455 }
456
457 return ret;
458}
459
460
461
462
463
464
465
466static void cleanup_timers(struct list_head *head,
467 cputime_t utime, cputime_t stime,
468 unsigned long long sum_exec_runtime)
469{
470 struct cpu_timer_list *timer, *next;
471 cputime_t ptime = cputime_add(utime, stime);
472
473 list_for_each_entry_safe(timer, next, head, entry) {
474 list_del_init(&timer->entry);
475 if (cputime_lt(timer->expires.cpu, ptime)) {
476 timer->expires.cpu = cputime_zero;
477 } else {
478 timer->expires.cpu = cputime_sub(timer->expires.cpu,
479 ptime);
480 }
481 }
482
483 ++head;
484 list_for_each_entry_safe(timer, next, head, entry) {
485 list_del_init(&timer->entry);
486 if (cputime_lt(timer->expires.cpu, utime)) {
487 timer->expires.cpu = cputime_zero;
488 } else {
489 timer->expires.cpu = cputime_sub(timer->expires.cpu,
490 utime);
491 }
492 }
493
494 ++head;
495 list_for_each_entry_safe(timer, next, head, entry) {
496 list_del_init(&timer->entry);
497 if (timer->expires.sched < sum_exec_runtime) {
498 timer->expires.sched = 0;
499 } else {
500 timer->expires.sched -= sum_exec_runtime;
501 }
502 }
503}
504
505
506
507
508
509
510void posix_cpu_timers_exit(struct task_struct *tsk)
511{
512 cleanup_timers(tsk->cpu_timers,
513 tsk->utime, tsk->stime, tsk->se.sum_exec_runtime);
514
515}
516void posix_cpu_timers_exit_group(struct task_struct *tsk)
517{
518 struct signal_struct *const sig = tsk->signal;
519
520 cleanup_timers(tsk->signal->cpu_timers,
521 cputime_add(tsk->utime, sig->utime),
522 cputime_add(tsk->stime, sig->stime),
523 tsk->se.sum_exec_runtime + sig->sum_sched_runtime);
524}
525
526static void clear_dead_task(struct k_itimer *timer, union cpu_time_count now)
527{
528
529
530
531
532 put_task_struct(timer->it.cpu.task);
533 timer->it.cpu.task = NULL;
534 timer->it.cpu.expires = cpu_time_sub(timer->it_clock,
535 timer->it.cpu.expires,
536 now);
537}
538
539static inline int expires_gt(cputime_t expires, cputime_t new_exp)
540{
541 return cputime_eq(expires, cputime_zero) ||
542 cputime_gt(expires, new_exp);
543}
544
545
546
547
548
549
550static void arm_timer(struct k_itimer *timer)
551{
552 struct task_struct *p = timer->it.cpu.task;
553 struct list_head *head, *listpos;
554 struct task_cputime *cputime_expires;
555 struct cpu_timer_list *const nt = &timer->it.cpu;
556 struct cpu_timer_list *next;
557
558 if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
559 head = p->cpu_timers;
560 cputime_expires = &p->cputime_expires;
561 } else {
562 head = p->signal->cpu_timers;
563 cputime_expires = &p->signal->cputime_expires;
564 }
565 head += CPUCLOCK_WHICH(timer->it_clock);
566
567 listpos = head;
568 list_for_each_entry(next, head, entry) {
569 if (cpu_time_before(timer->it_clock, nt->expires, next->expires))
570 break;
571 listpos = &next->entry;
572 }
573 list_add(&nt->entry, listpos);
574
575 if (listpos == head) {
576 union cpu_time_count *exp = &nt->expires;
577
578
579
580
581
582
583
584
585 switch (CPUCLOCK_WHICH(timer->it_clock)) {
586 case CPUCLOCK_PROF:
587 if (expires_gt(cputime_expires->prof_exp, exp->cpu))
588 cputime_expires->prof_exp = exp->cpu;
589 break;
590 case CPUCLOCK_VIRT:
591 if (expires_gt(cputime_expires->virt_exp, exp->cpu))
592 cputime_expires->virt_exp = exp->cpu;
593 break;
594 case CPUCLOCK_SCHED:
595 if (cputime_expires->sched_exp == 0 ||
596 cputime_expires->sched_exp > exp->sched)
597 cputime_expires->sched_exp = exp->sched;
598 break;
599 }
600 }
601}
602
603
604
605
606static void cpu_timer_fire(struct k_itimer *timer)
607{
608 if ((timer->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE) {
609
610
611
612 timer->it.cpu.expires.sched = 0;
613 } else if (unlikely(timer->sigq == NULL)) {
614
615
616
617
618 wake_up_process(timer->it_process);
619 timer->it.cpu.expires.sched = 0;
620 } else if (timer->it.cpu.incr.sched == 0) {
621
622
623
624 posix_timer_event(timer, 0);
625 timer->it.cpu.expires.sched = 0;
626 } else if (posix_timer_event(timer, ++timer->it_requeue_pending)) {
627
628
629
630
631
632
633 posix_cpu_timer_schedule(timer);
634 }
635}
636
637
638
639
640
641static int cpu_timer_sample_group(const clockid_t which_clock,
642 struct task_struct *p,
643 union cpu_time_count *cpu)
644{
645 struct task_cputime cputime;
646
647 thread_group_cputimer(p, &cputime);
648 switch (CPUCLOCK_WHICH(which_clock)) {
649 default:
650 return -EINVAL;
651 case CPUCLOCK_PROF:
652 cpu->cpu = cputime_add(cputime.utime, cputime.stime);
653 break;
654 case CPUCLOCK_VIRT:
655 cpu->cpu = cputime.utime;
656 break;
657 case CPUCLOCK_SCHED:
658 cpu->sched = cputime.sum_exec_runtime + task_delta_exec(p);
659 break;
660 }
661 return 0;
662}
663
664
665
666
667
668
669
670static int posix_cpu_timer_set(struct k_itimer *timer, int flags,
671 struct itimerspec *new, struct itimerspec *old)
672{
673 struct task_struct *p = timer->it.cpu.task;
674 union cpu_time_count old_expires, new_expires, old_incr, val;
675 int ret;
676
677 if (unlikely(p == NULL)) {
678
679
680
681 return -ESRCH;
682 }
683
684 new_expires = timespec_to_sample(timer->it_clock, &new->it_value);
685
686 read_lock(&tasklist_lock);
687
688
689
690
691
692 if (unlikely(p->sighand == NULL)) {
693 read_unlock(&tasklist_lock);
694 put_task_struct(p);
695 timer->it.cpu.task = NULL;
696 return -ESRCH;
697 }
698
699
700
701
702 BUG_ON(!irqs_disabled());
703
704 ret = 0;
705 old_incr = timer->it.cpu.incr;
706 spin_lock(&p->sighand->siglock);
707 old_expires = timer->it.cpu.expires;
708 if (unlikely(timer->it.cpu.firing)) {
709 timer->it.cpu.firing = -1;
710 ret = TIMER_RETRY;
711 } else
712 list_del_init(&timer->it.cpu.entry);
713
714
715
716
717
718
719
720
721
722 if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
723 cpu_clock_sample(timer->it_clock, p, &val);
724 } else {
725 cpu_timer_sample_group(timer->it_clock, p, &val);
726 }
727
728 if (old) {
729 if (old_expires.sched == 0) {
730 old->it_value.tv_sec = 0;
731 old->it_value.tv_nsec = 0;
732 } else {
733
734
735
736
737
738
739
740
741
742
743 bump_cpu_timer(timer, val);
744 if (cpu_time_before(timer->it_clock, val,
745 timer->it.cpu.expires)) {
746 old_expires = cpu_time_sub(
747 timer->it_clock,
748 timer->it.cpu.expires, val);
749 sample_to_timespec(timer->it_clock,
750 old_expires,
751 &old->it_value);
752 } else {
753 old->it_value.tv_nsec = 1;
754 old->it_value.tv_sec = 0;
755 }
756 }
757 }
758
759 if (unlikely(ret)) {
760
761
762
763
764
765
766 spin_unlock(&p->sighand->siglock);
767 read_unlock(&tasklist_lock);
768 goto out;
769 }
770
771 if (new_expires.sched != 0 && !(flags & TIMER_ABSTIME)) {
772 cpu_time_add(timer->it_clock, &new_expires, val);
773 }
774
775
776
777
778
779
780 timer->it.cpu.expires = new_expires;
781 if (new_expires.sched != 0 &&
782 cpu_time_before(timer->it_clock, val, new_expires)) {
783 arm_timer(timer);
784 }
785
786 spin_unlock(&p->sighand->siglock);
787 read_unlock(&tasklist_lock);
788
789
790
791
792
793 timer->it.cpu.incr = timespec_to_sample(timer->it_clock,
794 &new->it_interval);
795
796
797
798
799
800
801 timer->it_requeue_pending = (timer->it_requeue_pending + 2) &
802 ~REQUEUE_PENDING;
803 timer->it_overrun_last = 0;
804 timer->it_overrun = -1;
805
806 if (new_expires.sched != 0 &&
807 !cpu_time_before(timer->it_clock, val, new_expires)) {
808
809
810
811
812
813 cpu_timer_fire(timer);
814 }
815
816 ret = 0;
817 out:
818 if (old) {
819 sample_to_timespec(timer->it_clock,
820 old_incr, &old->it_interval);
821 }
822 return ret;
823}
824
825static void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec *itp)
826{
827 union cpu_time_count now;
828 struct task_struct *p = timer->it.cpu.task;
829 int clear_dead;
830
831
832
833
834 sample_to_timespec(timer->it_clock,
835 timer->it.cpu.incr, &itp->it_interval);
836
837 if (timer->it.cpu.expires.sched == 0) {
838 itp->it_value.tv_sec = itp->it_value.tv_nsec = 0;
839 return;
840 }
841
842 if (unlikely(p == NULL)) {
843
844
845
846
847 dead:
848 sample_to_timespec(timer->it_clock, timer->it.cpu.expires,
849 &itp->it_value);
850 return;
851 }
852
853
854
855
856 if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
857 cpu_clock_sample(timer->it_clock, p, &now);
858 clear_dead = p->exit_state;
859 } else {
860 read_lock(&tasklist_lock);
861 if (unlikely(p->sighand == NULL)) {
862
863
864
865
866
867 put_task_struct(p);
868 timer->it.cpu.task = NULL;
869 timer->it.cpu.expires.sched = 0;
870 read_unlock(&tasklist_lock);
871 goto dead;
872 } else {
873 cpu_timer_sample_group(timer->it_clock, p, &now);
874 clear_dead = (unlikely(p->exit_state) &&
875 thread_group_empty(p));
876 }
877 read_unlock(&tasklist_lock);
878 }
879
880 if (unlikely(clear_dead)) {
881
882
883
884
885
886 clear_dead_task(timer, now);
887 goto dead;
888 }
889
890 if (cpu_time_before(timer->it_clock, now, timer->it.cpu.expires)) {
891 sample_to_timespec(timer->it_clock,
892 cpu_time_sub(timer->it_clock,
893 timer->it.cpu.expires, now),
894 &itp->it_value);
895 } else {
896
897
898
899
900 itp->it_value.tv_nsec = 1;
901 itp->it_value.tv_sec = 0;
902 }
903}
904
905
906
907
908
909
910static void check_thread_timers(struct task_struct *tsk,
911 struct list_head *firing)
912{
913 int maxfire;
914 struct list_head *timers = tsk->cpu_timers;
915 struct signal_struct *const sig = tsk->signal;
916 unsigned long soft;
917
918 maxfire = 20;
919 tsk->cputime_expires.prof_exp = cputime_zero;
920 while (!list_empty(timers)) {
921 struct cpu_timer_list *t = list_first_entry(timers,
922 struct cpu_timer_list,
923 entry);
924 if (!--maxfire || cputime_lt(prof_ticks(tsk), t->expires.cpu)) {
925 tsk->cputime_expires.prof_exp = t->expires.cpu;
926 break;
927 }
928 t->firing = 1;
929 list_move_tail(&t->entry, firing);
930 }
931
932 ++timers;
933 maxfire = 20;
934 tsk->cputime_expires.virt_exp = cputime_zero;
935 while (!list_empty(timers)) {
936 struct cpu_timer_list *t = list_first_entry(timers,
937 struct cpu_timer_list,
938 entry);
939 if (!--maxfire || cputime_lt(virt_ticks(tsk), t->expires.cpu)) {
940 tsk->cputime_expires.virt_exp = t->expires.cpu;
941 break;
942 }
943 t->firing = 1;
944 list_move_tail(&t->entry, firing);
945 }
946
947 ++timers;
948 maxfire = 20;
949 tsk->cputime_expires.sched_exp = 0;
950 while (!list_empty(timers)) {
951 struct cpu_timer_list *t = list_first_entry(timers,
952 struct cpu_timer_list,
953 entry);
954 if (!--maxfire || tsk->se.sum_exec_runtime < t->expires.sched) {
955 tsk->cputime_expires.sched_exp = t->expires.sched;
956 break;
957 }
958 t->firing = 1;
959 list_move_tail(&t->entry, firing);
960 }
961
962
963
964
965 soft = ACCESS_ONCE(sig->rlim[RLIMIT_RTTIME].rlim_cur);
966 if (soft != RLIM_INFINITY) {
967 unsigned long hard =
968 ACCESS_ONCE(sig->rlim[RLIMIT_RTTIME].rlim_max);
969
970 if (hard != RLIM_INFINITY &&
971 tsk->rt.timeout > DIV_ROUND_UP(hard, USEC_PER_SEC/HZ)) {
972
973
974
975
976 __group_send_sig_info(SIGKILL, SEND_SIG_PRIV, tsk);
977 return;
978 }
979 if (tsk->rt.timeout > DIV_ROUND_UP(soft, USEC_PER_SEC/HZ)) {
980
981
982
983 if (soft < hard) {
984 soft += USEC_PER_SEC;
985 sig->rlim[RLIMIT_RTTIME].rlim_cur = soft;
986 }
987 printk(KERN_INFO
988 "RT Watchdog Timeout: %s[%d]\n",
989 tsk->comm, task_pid_nr(tsk));
990 __group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk);
991 }
992 }
993}
994
995static void stop_process_timers(struct signal_struct *sig)
996{
997 struct thread_group_cputimer *cputimer = &sig->cputimer;
998 unsigned long flags;
999
1000 spin_lock_irqsave(&cputimer->lock, flags);
1001 cputimer->running = 0;
1002 spin_unlock_irqrestore(&cputimer->lock, flags);
1003}
1004
1005static u32 onecputick;
1006
1007static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it,
1008 cputime_t *expires, cputime_t cur_time, int signo)
1009{
1010 if (cputime_eq(it->expires, cputime_zero))
1011 return;
1012
1013 if (cputime_ge(cur_time, it->expires)) {
1014 if (!cputime_eq(it->incr, cputime_zero)) {
1015 it->expires = cputime_add(it->expires, it->incr);
1016 it->error += it->incr_error;
1017 if (it->error >= onecputick) {
1018 it->expires = cputime_sub(it->expires,
1019 cputime_one_jiffy);
1020 it->error -= onecputick;
1021 }
1022 } else {
1023 it->expires = cputime_zero;
1024 }
1025
1026 trace_itimer_expire(signo == SIGPROF ?
1027 ITIMER_PROF : ITIMER_VIRTUAL,
1028 tsk->signal->leader_pid, cur_time);
1029 __group_send_sig_info(signo, SEND_SIG_PRIV, tsk);
1030 }
1031
1032 if (!cputime_eq(it->expires, cputime_zero) &&
1033 (cputime_eq(*expires, cputime_zero) ||
1034 cputime_lt(it->expires, *expires))) {
1035 *expires = it->expires;
1036 }
1037}
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047static inline int task_cputime_zero(const struct task_cputime *cputime)
1048{
1049 if (cputime_eq(cputime->utime, cputime_zero) &&
1050 cputime_eq(cputime->stime, cputime_zero) &&
1051 cputime->sum_exec_runtime == 0)
1052 return 1;
1053 return 0;
1054}
1055
1056
1057
1058
1059
1060
1061static void check_process_timers(struct task_struct *tsk,
1062 struct list_head *firing)
1063{
1064 int maxfire;
1065 struct signal_struct *const sig = tsk->signal;
1066 cputime_t utime, ptime, virt_expires, prof_expires;
1067 unsigned long long sum_sched_runtime, sched_expires;
1068 struct list_head *timers = sig->cpu_timers;
1069 struct task_cputime cputime;
1070 unsigned long soft;
1071
1072
1073
1074
1075 thread_group_cputimer(tsk, &cputime);
1076 utime = cputime.utime;
1077 ptime = cputime_add(utime, cputime.stime);
1078 sum_sched_runtime = cputime.sum_exec_runtime;
1079 maxfire = 20;
1080 prof_expires = cputime_zero;
1081 while (!list_empty(timers)) {
1082 struct cpu_timer_list *tl = list_first_entry(timers,
1083 struct cpu_timer_list,
1084 entry);
1085 if (!--maxfire || cputime_lt(ptime, tl->expires.cpu)) {
1086 prof_expires = tl->expires.cpu;
1087 break;
1088 }
1089 tl->firing = 1;
1090 list_move_tail(&tl->entry, firing);
1091 }
1092
1093 ++timers;
1094 maxfire = 20;
1095 virt_expires = cputime_zero;
1096 while (!list_empty(timers)) {
1097 struct cpu_timer_list *tl = list_first_entry(timers,
1098 struct cpu_timer_list,
1099 entry);
1100 if (!--maxfire || cputime_lt(utime, tl->expires.cpu)) {
1101 virt_expires = tl->expires.cpu;
1102 break;
1103 }
1104 tl->firing = 1;
1105 list_move_tail(&tl->entry, firing);
1106 }
1107
1108 ++timers;
1109 maxfire = 20;
1110 sched_expires = 0;
1111 while (!list_empty(timers)) {
1112 struct cpu_timer_list *tl = list_first_entry(timers,
1113 struct cpu_timer_list,
1114 entry);
1115 if (!--maxfire || sum_sched_runtime < tl->expires.sched) {
1116 sched_expires = tl->expires.sched;
1117 break;
1118 }
1119 tl->firing = 1;
1120 list_move_tail(&tl->entry, firing);
1121 }
1122
1123
1124
1125
1126 check_cpu_itimer(tsk, &sig->it[CPUCLOCK_PROF], &prof_expires, ptime,
1127 SIGPROF);
1128 check_cpu_itimer(tsk, &sig->it[CPUCLOCK_VIRT], &virt_expires, utime,
1129 SIGVTALRM);
1130 soft = ACCESS_ONCE(sig->rlim[RLIMIT_CPU].rlim_cur);
1131 if (soft != RLIM_INFINITY) {
1132 unsigned long psecs = cputime_to_secs(ptime);
1133 unsigned long hard =
1134 ACCESS_ONCE(sig->rlim[RLIMIT_CPU].rlim_max);
1135 cputime_t x;
1136 if (psecs >= hard) {
1137
1138
1139
1140
1141 __group_send_sig_info(SIGKILL, SEND_SIG_PRIV, tsk);
1142 return;
1143 }
1144 if (psecs >= soft) {
1145
1146
1147
1148 __group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk);
1149 if (soft < hard) {
1150 soft++;
1151 sig->rlim[RLIMIT_CPU].rlim_cur = soft;
1152 }
1153 }
1154 x = secs_to_cputime(soft);
1155 if (cputime_eq(prof_expires, cputime_zero) ||
1156 cputime_lt(x, prof_expires)) {
1157 prof_expires = x;
1158 }
1159 }
1160
1161 sig->cputime_expires.prof_exp = prof_expires;
1162 sig->cputime_expires.virt_exp = virt_expires;
1163 sig->cputime_expires.sched_exp = sched_expires;
1164 if (task_cputime_zero(&sig->cputime_expires))
1165 stop_process_timers(sig);
1166}
1167
1168
1169
1170
1171
1172void posix_cpu_timer_schedule(struct k_itimer *timer)
1173{
1174 struct task_struct *p = timer->it.cpu.task;
1175 union cpu_time_count now;
1176
1177 if (unlikely(p == NULL))
1178
1179
1180
1181 goto out;
1182
1183
1184
1185
1186 if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
1187 cpu_clock_sample(timer->it_clock, p, &now);
1188 bump_cpu_timer(timer, now);
1189 if (unlikely(p->exit_state)) {
1190 clear_dead_task(timer, now);
1191 goto out;
1192 }
1193 read_lock(&tasklist_lock);
1194 spin_lock(&p->sighand->siglock);
1195 } else {
1196 read_lock(&tasklist_lock);
1197 if (unlikely(p->sighand == NULL)) {
1198
1199
1200
1201
1202 put_task_struct(p);
1203 timer->it.cpu.task = p = NULL;
1204 timer->it.cpu.expires.sched = 0;
1205 goto out_unlock;
1206 } else if (unlikely(p->exit_state) && thread_group_empty(p)) {
1207
1208
1209
1210
1211
1212 clear_dead_task(timer, now);
1213 goto out_unlock;
1214 }
1215 spin_lock(&p->sighand->siglock);
1216 cpu_timer_sample_group(timer->it_clock, p, &now);
1217 bump_cpu_timer(timer, now);
1218
1219 }
1220
1221
1222
1223
1224 BUG_ON(!irqs_disabled());
1225 arm_timer(timer);
1226 spin_unlock(&p->sighand->siglock);
1227
1228out_unlock:
1229 read_unlock(&tasklist_lock);
1230
1231out:
1232 timer->it_overrun_last = timer->it_overrun;
1233 timer->it_overrun = -1;
1234 ++timer->it_requeue_pending;
1235}
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247static inline int task_cputime_expired(const struct task_cputime *sample,
1248 const struct task_cputime *expires)
1249{
1250 if (!cputime_eq(expires->utime, cputime_zero) &&
1251 cputime_ge(sample->utime, expires->utime))
1252 return 1;
1253 if (!cputime_eq(expires->stime, cputime_zero) &&
1254 cputime_ge(cputime_add(sample->utime, sample->stime),
1255 expires->stime))
1256 return 1;
1257 if (expires->sum_exec_runtime != 0 &&
1258 sample->sum_exec_runtime >= expires->sum_exec_runtime)
1259 return 1;
1260 return 0;
1261}
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273static inline int fastpath_timer_check(struct task_struct *tsk)
1274{
1275 struct signal_struct *sig;
1276
1277 if (!task_cputime_zero(&tsk->cputime_expires)) {
1278 struct task_cputime task_sample = {
1279 .utime = tsk->utime,
1280 .stime = tsk->stime,
1281 .sum_exec_runtime = tsk->se.sum_exec_runtime
1282 };
1283
1284 if (task_cputime_expired(&task_sample, &tsk->cputime_expires))
1285 return 1;
1286 }
1287
1288 sig = tsk->signal;
1289 if (sig->cputimer.running) {
1290 struct task_cputime group_sample;
1291
1292 spin_lock(&sig->cputimer.lock);
1293 group_sample = sig->cputimer.cputime;
1294 spin_unlock(&sig->cputimer.lock);
1295
1296 if (task_cputime_expired(&group_sample, &sig->cputime_expires))
1297 return 1;
1298 }
1299
1300 return 0;
1301}
1302
1303
1304
1305
1306
1307
1308void run_posix_cpu_timers(struct task_struct *tsk)
1309{
1310 LIST_HEAD(firing);
1311 struct k_itimer *timer, *next;
1312 unsigned long flags;
1313
1314 BUG_ON(!irqs_disabled());
1315
1316
1317
1318
1319
1320 if (!fastpath_timer_check(tsk))
1321 return;
1322
1323 if (!lock_task_sighand(tsk, &flags))
1324 return;
1325
1326
1327
1328
1329
1330 check_thread_timers(tsk, &firing);
1331
1332
1333
1334
1335 if (tsk->signal->cputimer.running)
1336 check_process_timers(tsk, &firing);
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346 unlock_task_sighand(tsk, &flags);
1347
1348
1349
1350
1351
1352
1353
1354 list_for_each_entry_safe(timer, next, &firing, it.cpu.entry) {
1355 int cpu_firing;
1356
1357 spin_lock(&timer->it_lock);
1358 list_del_init(&timer->it.cpu.entry);
1359 cpu_firing = timer->it.cpu.firing;
1360 timer->it.cpu.firing = 0;
1361
1362
1363
1364
1365
1366 if (likely(cpu_firing >= 0))
1367 cpu_timer_fire(timer);
1368 spin_unlock(&timer->it_lock);
1369 }
1370}
1371
1372
1373
1374
1375
1376void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx,
1377 cputime_t *newval, cputime_t *oldval)
1378{
1379 union cpu_time_count now;
1380
1381 BUG_ON(clock_idx == CPUCLOCK_SCHED);
1382 cpu_timer_sample_group(clock_idx, tsk, &now);
1383
1384 if (oldval) {
1385
1386
1387
1388
1389
1390 if (!cputime_eq(*oldval, cputime_zero)) {
1391 if (cputime_le(*oldval, now.cpu)) {
1392
1393 *oldval = cputime_one_jiffy;
1394 } else {
1395 *oldval = cputime_sub(*oldval, now.cpu);
1396 }
1397 }
1398
1399 if (cputime_eq(*newval, cputime_zero))
1400 return;
1401 *newval = cputime_add(*newval, now.cpu);
1402 }
1403
1404
1405
1406
1407
1408 switch (clock_idx) {
1409 case CPUCLOCK_PROF:
1410 if (expires_gt(tsk->signal->cputime_expires.prof_exp, *newval))
1411 tsk->signal->cputime_expires.prof_exp = *newval;
1412 break;
1413 case CPUCLOCK_VIRT:
1414 if (expires_gt(tsk->signal->cputime_expires.virt_exp, *newval))
1415 tsk->signal->cputime_expires.virt_exp = *newval;
1416 break;
1417 }
1418}
1419
1420static int do_cpu_nanosleep(const clockid_t which_clock, int flags,
1421 struct timespec *rqtp, struct itimerspec *it)
1422{
1423 struct k_itimer timer;
1424 int error;
1425
1426
1427
1428
1429 memset(&timer, 0, sizeof timer);
1430 spin_lock_init(&timer.it_lock);
1431 timer.it_clock = which_clock;
1432 timer.it_overrun = -1;
1433 error = posix_cpu_timer_create(&timer);
1434 timer.it_process = current;
1435 if (!error) {
1436 static struct itimerspec zero_it;
1437
1438 memset(it, 0, sizeof *it);
1439 it->it_value = *rqtp;
1440
1441 spin_lock_irq(&timer.it_lock);
1442 error = posix_cpu_timer_set(&timer, flags, it, NULL);
1443 if (error) {
1444 spin_unlock_irq(&timer.it_lock);
1445 return error;
1446 }
1447
1448 while (!signal_pending(current)) {
1449 if (timer.it.cpu.expires.sched == 0) {
1450
1451
1452
1453 spin_unlock_irq(&timer.it_lock);
1454 return 0;
1455 }
1456
1457
1458
1459
1460 __set_current_state(TASK_INTERRUPTIBLE);
1461 spin_unlock_irq(&timer.it_lock);
1462 schedule();
1463 spin_lock_irq(&timer.it_lock);
1464 }
1465
1466
1467
1468
1469 sample_to_timespec(which_clock, timer.it.cpu.expires, rqtp);
1470 posix_cpu_timer_set(&timer, 0, &zero_it, it);
1471 spin_unlock_irq(&timer.it_lock);
1472
1473 if ((it->it_value.tv_sec | it->it_value.tv_nsec) == 0) {
1474
1475
1476
1477 return 0;
1478 }
1479
1480 error = -ERESTART_RESTARTBLOCK;
1481 }
1482
1483 return error;
1484}
1485
1486static long posix_cpu_nsleep_restart(struct restart_block *restart_block);
1487
1488static int posix_cpu_nsleep(const clockid_t which_clock, int flags,
1489 struct timespec *rqtp, struct timespec __user *rmtp)
1490{
1491 struct restart_block *restart_block =
1492 ¤t_thread_info()->restart_block;
1493 struct itimerspec it;
1494 int error;
1495
1496
1497
1498
1499 if (CPUCLOCK_PERTHREAD(which_clock) &&
1500 (CPUCLOCK_PID(which_clock) == 0 ||
1501 CPUCLOCK_PID(which_clock) == current->pid))
1502 return -EINVAL;
1503
1504 error = do_cpu_nanosleep(which_clock, flags, rqtp, &it);
1505
1506 if (error == -ERESTART_RESTARTBLOCK) {
1507
1508 if (flags & TIMER_ABSTIME)
1509 return -ERESTARTNOHAND;
1510
1511
1512
1513 if (rmtp && copy_to_user(rmtp, &it.it_value, sizeof *rmtp))
1514 return -EFAULT;
1515
1516 restart_block->fn = posix_cpu_nsleep_restart;
1517 restart_block->nanosleep.clockid = which_clock;
1518 restart_block->nanosleep.rmtp = rmtp;
1519 restart_block->nanosleep.expires = timespec_to_ns(rqtp);
1520 }
1521 return error;
1522}
1523
1524static long posix_cpu_nsleep_restart(struct restart_block *restart_block)
1525{
1526 clockid_t which_clock = restart_block->nanosleep.clockid;
1527 struct timespec t;
1528 struct itimerspec it;
1529 int error;
1530
1531 t = ns_to_timespec(restart_block->nanosleep.expires);
1532
1533 error = do_cpu_nanosleep(which_clock, TIMER_ABSTIME, &t, &it);
1534
1535 if (error == -ERESTART_RESTARTBLOCK) {
1536 struct timespec __user *rmtp = restart_block->nanosleep.rmtp;
1537
1538
1539
1540 if (rmtp && copy_to_user(rmtp, &it.it_value, sizeof *rmtp))
1541 return -EFAULT;
1542
1543 restart_block->nanosleep.expires = timespec_to_ns(&t);
1544 }
1545 return error;
1546
1547}
1548
1549#define PROCESS_CLOCK MAKE_PROCESS_CPUCLOCK(0, CPUCLOCK_SCHED)
1550#define THREAD_CLOCK MAKE_THREAD_CPUCLOCK(0, CPUCLOCK_SCHED)
1551
1552static int process_cpu_clock_getres(const clockid_t which_clock,
1553 struct timespec *tp)
1554{
1555 return posix_cpu_clock_getres(PROCESS_CLOCK, tp);
1556}
1557static int process_cpu_clock_get(const clockid_t which_clock,
1558 struct timespec *tp)
1559{
1560 return posix_cpu_clock_get(PROCESS_CLOCK, tp);
1561}
1562static int process_cpu_timer_create(struct k_itimer *timer)
1563{
1564 timer->it_clock = PROCESS_CLOCK;
1565 return posix_cpu_timer_create(timer);
1566}
1567static int process_cpu_nsleep(const clockid_t which_clock, int flags,
1568 struct timespec *rqtp,
1569 struct timespec __user *rmtp)
1570{
1571 return posix_cpu_nsleep(PROCESS_CLOCK, flags, rqtp, rmtp);
1572}
1573static long process_cpu_nsleep_restart(struct restart_block *restart_block)
1574{
1575 return -EINVAL;
1576}
1577static int thread_cpu_clock_getres(const clockid_t which_clock,
1578 struct timespec *tp)
1579{
1580 return posix_cpu_clock_getres(THREAD_CLOCK, tp);
1581}
1582static int thread_cpu_clock_get(const clockid_t which_clock,
1583 struct timespec *tp)
1584{
1585 return posix_cpu_clock_get(THREAD_CLOCK, tp);
1586}
1587static int thread_cpu_timer_create(struct k_itimer *timer)
1588{
1589 timer->it_clock = THREAD_CLOCK;
1590 return posix_cpu_timer_create(timer);
1591}
1592
1593struct k_clock clock_posix_cpu = {
1594 .clock_getres = posix_cpu_clock_getres,
1595 .clock_set = posix_cpu_clock_set,
1596 .clock_get = posix_cpu_clock_get,
1597 .timer_create = posix_cpu_timer_create,
1598 .nsleep = posix_cpu_nsleep,
1599 .nsleep_restart = posix_cpu_nsleep_restart,
1600 .timer_set = posix_cpu_timer_set,
1601 .timer_del = posix_cpu_timer_del,
1602 .timer_get = posix_cpu_timer_get,
1603};
1604
1605static __init int init_posix_cpu_timers(void)
1606{
1607 struct k_clock process = {
1608 .clock_getres = process_cpu_clock_getres,
1609 .clock_get = process_cpu_clock_get,
1610 .timer_create = process_cpu_timer_create,
1611 .nsleep = process_cpu_nsleep,
1612 .nsleep_restart = process_cpu_nsleep_restart,
1613 };
1614 struct k_clock thread = {
1615 .clock_getres = thread_cpu_clock_getres,
1616 .clock_get = thread_cpu_clock_get,
1617 .timer_create = thread_cpu_timer_create,
1618 };
1619 struct timespec ts;
1620
1621 posix_timers_register_clock(CLOCK_PROCESS_CPUTIME_ID, &process);
1622 posix_timers_register_clock(CLOCK_THREAD_CPUTIME_ID, &thread);
1623
1624 cputime_to_timespec(cputime_one_jiffy, &ts);
1625 onecputick = ts.tv_nsec;
1626 WARN_ON(ts.tv_sec != 0);
1627
1628 return 0;
1629}
1630__initcall(init_posix_cpu_timers);
1631